Influence of the synthesis parameters onto nucleation and crystallization of five new tin-sulfur containing compounds.

The distinct control of the synthesis parameters achieved crystallization of five new inorganic-organic hybrid tin sulfides with 1,10-phenanthroline (phen) as the organic component: {[Mn(phen)2]2(μ2-Sn2S6)} (1, 3), {[Mn(phen)2]2(μ2-Sn2S6)}·phen (2), {[Mn(phen)2]2(μ2-Sn2S6)}·phen·H2O (4), and {[Mn(phen)2]2[μ-η(2)-η(2)-SnS4]2[Mn(phen)]2}·H2O (5). Compounds 1, 3, and 4 occur successively under static conditions by increasing the reaction time up to 8 weeks. Stirring the reaction mixtures and keeping the educt ratio constant allow preparation of distinct phase pure samples within very short reaction times. At higher autogenous pressure, crystallization and conversion of several compounds are suppressed, and only 1 crystallized. Compound 2 could only be obtained in glass tubes at low pH value of the reaction mixture or at low amine concentration. Adjusting the pH value of the solution, the concentration, and the volume of the solvent, compounds 1-4 crystallize sequentially and were successively converted into each other. Results of thermal stability experiments and solubility studies suggest that compounds 1 and 3 are polymorphs following the density rule. Compounds 2 and 4 may be viewed as pseudopolymorphs of 1 and 3.